Long-term outcome of horizontal root fractures in 33 young permanent teeth: a clinical retrospective study

Background: Horizontal root fracture is a special type of dental trauma. The objective of this study was to evaluate the healing outcome and influencing factors of young permanent tooth horizontal root fractures. Methods: A retrospective study (Exclusion of 9 patients with lost-to-follow-up status) included 33 young permanent teeth with horizontal root fractures from 26 children (mean age 9.31 ± 1.76 years) treated from 2020 to 2022 with ≥24-month of follow-up. Treatment followed the International Association of Dental Traumatology (IADT) guidelines (repositioning, flexible fixation, long-term follow-up, apexification for infections). Healing was classified (Andreasen criteria) as calcified, connective, bone-connective tissue, or inflammatory (non-healing). Root development (Nolla 5–8 (very immature) vs. 9 (immature)) and fracture location (coronal/middle/apical 1/3) were analyzed. SPSS 13.0 was used for the chi-square test or Fisher’s test (α = 0.05). Results: Overall healing rate was 93.9% (31/33): 18.18%calcified, 54.55% connective, 21.21% bone-connective tissue, and 6.06% inflammatory healing. Six teeth required apexification; 1 had diffuse pulp calcification. Fracture location, root development, and displacement did not affect overall healing (p > 0.05), but in the chi-square test, root development significantly influenced calcified healing (p < 0.05): 50% (3/6) in very immature vs. 11.1% (3/27) in immature teeth. However, in the Fisher’s test, it did not have statistical significance. Conclusions: Standardized treatment yields favorable outcomes. Root development (not location/displacement) affects calcified healing, with higher rates in very immature teeth. Emphasis on timely treatment, long-term follow-up, and pulp preservation in very immature teeth is recommended.

Horizontal root fractures; Healing rate; Influencing factors; Young permanent teeth

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